diff --git a/templates/deployment.yaml b/templates/deployment.yaml
index 09b9b83..528fd75 100644
--- a/templates/deployment.yaml
+++ b/templates/deployment.yaml
@@ -147,4 +147,5 @@ spec:
         - name: ssh-key
           secret:
             secretName: {{ .Values.updater.ssh.secretName }}
+            defaultMode: 0400
         {{- end }}